Electric powered wheelchairs are generally controlled by joystick assemblies, operably coupled to electric drive motors, which permit an operator to accelerate, steer and brake the wheelchair from an operating position. Because some wheelchair occupants are severely impaired, physically, conventional vehicle steering means are often inappropriate and difficult to operate for these individuals. Joysticks, on the other hand, allow those severely impaired to operate the movement of the wheelchair simply by positioning a joystick knob with one hand in the desired direction of movement of the wheelchair.
Preferably, the joystick device is optimally located where the operator can comfortably rest their arm on the wheelchair armrest from the operating position and operate the joystick knob free of discomfort. This position generally places the joystick knob just forward of the front portion of the armrest at a height where the joystick may be operated by the user while seated in the operating position. Such a position optimally places the joystick knob for accessibility permitting the user to rests their arm on the wheelchair armrest.
The joystick is often mounted to a distal end of an elongated rod member which is disposed alongside the wheelchair armrest or a side portion of the wheelchair frame. This rod member is releasably coupled to a bracket member mounted to the armrest or the wheelchair frame member and formed to slidably receive the rod member. Hence, the rod member and the joystick carried thereby can slide forward, away from the armrest, or rearward, toward the armrest, in a direction along the longitudinal axis of the rod member for length adjustment purposes.
While these joystick mounting assemblies have been adequate to adjust the location of the joystick device along the longitudinal axis of the rod member, several operational problems are inherent in these designs. A locking mechanism, to secure the rod member relative to the bracket member, must be loosened, usually by turning a knob, in order to permit the rod member to slide forward or rearward. Subsequently, the latch mechanism must be tightened in order to retain the positioning of the joystick device. Moreover, to move the joystick each time, this sequence of events must be repeated which tends to be difficult and laborious to those severely impaired.
Another problem that has been encountered in connection with these prior art joystick mounting assemblies is that the mounting assembly always positions the joystick device forward of the armrest. Because of the occupant's limited mobility while seated in the operating position, it is often desirable to position the wheelchair as close as possible to working table, office desk or the like for greater access, convenience and practical working environment. Thus, in situations where the table is placed at a height similar to that of the joystick device, the wheelchair may only be moved as close to the table as the joystick device will permit. Traditional joystick mounting assemblies may be retracted somewhat in the direction along the longitudinal axis of the rod member; however, without removal of the joystick, the joystick device is still positioned between the armrest and the table.
Finally, ingress and egress to and from the operating position of the wheelchair is more difficult since the joystick device projects forward from the armrest which impairs passage to the wheelchair seat.